The invention relates to a mobile crane having an undercarriage and a superstructure rotatable with respect to the undercarriage about an axis of rotation and to a ballast receiving apparatus arranged at the superstructure and having at least one ballasting cylinder for receiving ballast.
Mobile cranes require a working space determined by the type of construction at a construction site to ensure a full and safety-compliant mode of operation. There is often only limited space available due to projecting edges at the construction site which can be produced by walls, planting or further work equipment.
In this respect, the required working space is substantially determined by two factors. Whereas the first factor is represented by the support base which is defined by the respective support apparatus depending on the equipping state, the superstructure radius of rotation as the second major factor, that is the outermost edge of the superstructure on the rotation of the superstructure about the undercarriage, determines the working space of the mobile crane. As a rule this superstructure radius of rotation is influenced by the mounted ballast plates or by the apparatus for receiving the ballast plates since an installed ballast receiving apparatus, including the ballast plates, frequently projects the furthest out of the superstructure.
If the superstructure radius of rotation is reduced, the required working space for the mobile crane admittedly reduces on the one side. However, on the other side, the distance from the center of gravity of the ballast to the axis of rotation of the superstructure about the undercarriage is reduced. This in turn, however, reduces the torque which acts against the load torque caused by the load.
DE 20 2010 002 364 U1 already looks into this problem and provides a mobile crane which has a first and a second ballast receiving apparatus which differ from one another with respect to their physical dimensions and which are selectively releasably connected or connectable to the superstructure of the mobile crane. The ballast receiving apparatus used defines the superstructure radius of rotation which is described by the outermost component or the outermost edge of the ballast receiving apparatus in the radial direction on a rotary movement of the superstructure. The support base and the superstructure radius of rotation can be matched to one another by the selective installation of the first or second ballast receiving apparatus on the mobile crane. This solution admittedly optimizes the superstructure radius of rotation, but has the result that two separate ballast receiving apparatus have to be provided and have to be kept available by the operator of the mobile crane.